Data Validation Foundation Class

This class traps for data conflicts on buffered data.

Category	Data Editing
Default Catalog	Visual FoxPro Catalog\Foundation Classes\Data Query
Class	_datachecker
Base Class	Custom
Class Library	_datanav.vcx
Parent Class	_custom
Sample	...\Samples\Solution\Ffc\conflicts.scx

Remarks

To use, drop the class on a project or form or, from the Component Gallery Item shortcut menu, select Add to Project or Add to Form. When you add the class to a form, you need to specify the appropriate property values. When you drop the class on a project, you can choose between adding the class or creating a subclass.

See Guidelines for Using Visual FoxPro Foundation Classes for more information on using foundation classes.

Properties, Events, Methods	Description
HandleRecord method	Compares the current value, old value, and original value on disk of each field, displaying a message box if a change or conflict is detected. Syntax: HandleRecord(lnScope) Return: nReturn Arguments: lnScope specifies the degree of validation: 0 = check for conflicts1 = check for conflicts and verify changes. nReturn specifies the action taken: 0 = No Change 1 = Successful Change 2 = Unable to make change
String method	Called by the HandleRecord method, returns a character equivalent of the passed value. Returns only a notification for memo fields. Syntax: String(luValue) Return: none Arguments: luValue specifies the value to be checked.
VerifyChanges method	Prompts a user to save all changes made to a table or record. Syntax: VerifyChanges( ) Return: none Arguments: none
VerifyEachChange method	Prompts a user to confirm each change made. Syntax: VerifyEachChange( ) Return: none Arguments: none
CheckcConflicts method	Notifies a user when data has changed after record editing started. Syntax: CheckcConflicts( ) Return: none Arguments: none

See Also

Concepts

Guidelines for Using Visual FoxPro Foundation Classes

Reference

Visual FoxPro Foundation Classes A-Z

Other Resources

Foundation Class Samples